From what I saw they have nicer merges of the tubes than some of the later versions. Glad you saved them.
I have a set of Headers by Ed that would be an interesting back to back comparison in the 1/4 mile. They're relatively easy install but hang too low for general street use.
I've never tried Ed's. I went manifolds only because of the room, durability, and simplicity. I may try to work with the drop downs on the spitfires, as they've been beat in quite a bit. LOL.